Mike Konrad

Mike Konrad has submitted responses to the following questions.

Baking After Cleaning Hand Placed Parts
Most inline cleaning systems utilize air-knife technology to blow-off water from the assembly after final rinse. Some inline machines add ...

Water Wash vs. No-clean
That's a great question and is quite topical. If one reflows a circuit assembly using rosin or water soluble solder ...

Cleanliness Requirement for Populated Printed Boards
The standard referenced in the question is VDA 19.1 Inspection of Technical Cleanliness-Particulate Contamination of Functionally Relevant Automotive Components. A ...

Cleaning Under Low Clearance Components
The question "Are my fears about properly cleaning water-clean flux from under low-profile parts justified" can be answered in a ...

No-Clean Flux Residue After Selective Soldering
There are published standards that dictate the amount of ionic residue can be left on an assembly. Many of these ...

Pros and Cons of Cleaning No-clean
I would like to change the question from "Pros and Cons of Cleaning No-Clean" to "Pros and Cons of Cleaning". ...

Hot or Cold DI Water Rinse
There is little advantage to heat the rinse water in a defluxing process. Keep in mind the solubilization of the ...

Un-cleaned PCB Assemblies Potted
In all likelihood, this assembly will suffer multiple failures. First, the coating over OA flux will most likely fail due ...

Class 3 Cleaning Requirements
IPCTM650 describes cleanliness testing methods and required results.Unfortunately, the cleanliness results outlined in both military and IPC standards were written ...

Dewetting of Acrylic Conformal Coating
You seem to be missing one process step... cleaning. You should remove all contamination from the assembly after reflow prior ...

Stagnant DI Water Usage
Actually, water left in ion exchange resin tanks will maintain a high level of resistivity. It is common for water ...

Use of Nitrogen for Hand Soldering
I am not aware of "fluxless" soldering using metallic solder (not conductive adhesives). One should consider the other residues potentially ...

Organic Flux Residue Concerns
Of all of the flux types, OA (Organic Acid) flux is the absolute worst to leave on an assembly. OA ...

Cleaning No-Clean Solder Paste
The removal of no-clean flux residues requires four things:Defluxing chemical Mechanical energy Complete coverage Proper rinsing Water alone will not ...

Is Baking Required After Aqueous Cleaning?
The true answer is that some assemblies may require baking and some may not. It really depends on what type ...

Ultrasonic Cleaning Causing Damage
In the past, there have been concerns about the possibility of ultrasonic energy damaging specific types of components such as ...

What is the Proper DI Water Resistivity
There is not a published specification applied to removing flux from populated assemblies. As a practical suggestion, it is important ...

IPA to clean 'lead-free'
Your question is very timely. No-clean flux leaves behind residue. In many cases, the residue does not cause harm to ...

Problem with 'No Clean' Solder Flux Residue
Just to be clear, no-clean does not mean that it does not have to be cleaned. It simply means that ...

Recommended DI Water Conductivity For Ultrasonic Cleaning
This is a very wide open question. The correct answer is that the DI water resistivity is whatever you put ...

Substance causing open BGA solder joints
Localized extraction testing is one option. Foresite (an analytical laboratory in Indiana) provides both bulk and localized extraction testing. Using ...

Frequency range for ultrasonic cleaning
In almost all cases, 20 kHz is used. A sweep frequency ensures that the actually frequency moves +/- 5 kHz. ...

Affects of Ultrasonic Cleaning
The answer is no. The answer is yes. Take your pick. There are two schools on this subject. Smart, intelligent, ...

Clean water soluble flux
The success of a defluxing process relies on two capabilities, the equipment's ability to deliver water (or wash solution) to ...

Clean a no clean PCBA
As a manufacturer of automatic defluxing systems for more than 16 years, I can tell you that the majority of ...

Best Board Cleaning Methodology
Spray-in-air is the most effective method in both the removal of post reflow flux residues and post reflow solder balls. ...

Deflux Eutectic and Lead-Free Assemblies
The correct answer is Yes and No. Technically speaking, both lead and lead-free flux residues may me cleaned at the ...

Cleaning tin-lead and lead-free boards
The answer depends entirely on the specific cleaning system you are currently using. Lead free is more difficult to clean ...

Best method to clean "no-clean" solder paste
Misprint cleaning is best accomplished with the use of an ultrasonic stencil cleaning system. Hand cleaning frequently pushes solder paste ...

Aqueous Cleaning Process
First, localized cleaning is actually localized flux dilution. To fully remove flux residues from a localized area, one must clean ...

Aqueous cleaner water tested for the Lead
Discharge water from an aqueous cleaning system should be tested for any banned or limit controlled substances. I doubt you ...

Which cleaning solution do you recommend to avoid damage to relay contacts, coils and filters?
Unsealed components present issues in most cleaning processes. AVD (waterless) cleaning processes may present a solution but at a high ...

What type of cleaner method is preferred for lead-free stencils?
Fist, the answer is the same regardless of the specific paste type, (leaded or non-leaded). High pressure sprays should never ...

Pre-wash boards prior to conformal coating
Conformal coating requires a clean, dry board. Conformal coating adhesion is negatively effected by board contamination. In applications where conformal ...

Separate wash systems for leaded and non-lead boards?
As with so many answers, yes and no. From a strictly wash standpoint, there is no need to segregate lead ...

Batch washing machine request
There are several manufacturers of batch-format de-fluxing systems on available today. My reply will address two aspects of your questions. ...